Double suction unit

ABSTRACT

An apparatus for removing both cut threads and trimmed edges from the working area of a sewing machine with a unit having a first air passage coupled to the area for removing trimmed edges, a second air passage coupled to the area for removing trimmed edges and opening into the first passage at an acute angle in an elliptically shaped opening to inject an air stream into the first passage to transfer momentum and cause air flow, the second passage comprising two tubular members one inside the other with the outer opening into the first passage, and a third air passage injecting air at a pressure above atmospheric pressure at an angle in an elliptically shaped opening to transfer momentum and create air flow through said second passage.

United States Patent Dunne Dec. 10, 1974 DOUBLE SUCTION UNIT PrimaryExaminerl-l. Hampton Hunter [75] Inventor: Owen F. Dunne, Tiverton, R.I.Attorney Agent or Flrm cushman Darby &

Cushman [73] Assignee: Clevepak Corporation, New York,

57 ABSTRACT [22] Filed: Mar. 7, 1974 An apparatus for removing both cutthreads and 1 1 pp N05 4491082 trimmed edges from the working area of asewing machine with a unit having a first air passage coupled to 52 US.(:1 112/218 R, 115/409, 417/174 the area for removing trimmed edges 8sectmd air 51 1m. (:1 D05b 81/00 Passage P t0 the area removing trimmed[58] Field of Search 112/218 R, DIG. 1, DIG. 2, edges and Opening intothe first Passage at an acute 112/DIG 3 122 129 252; 417/1 9 176 anglein an elliptically shaped opening to inject an 311' 179, 180; 15/408,409, 345 346 stream into the first passage to transfer momentum andcause air flow, the second passage comprising two [56] References Citedtubular members one inside the other with the outer UNITED STATESPATENTS opening into the first passage, and a third ,air passageinjecting air at a pressure above atmospheric pressure 2,899,971 8/1959Munter .1 417/174 X at an angle in an ellipticany Shaped opening totransfer T 1 5;3 5:3 5 3 25; momentum and create air flow through saidsecond 3:223:697 12/1965 Ball et a1 417/174 x Passage 3,525,474 8/1970Von Ohain et al. 417/169 6 Claims, 3 Drawing I igures Hll DOUBLE SUCTIONUNIT The invention relates to an apparatus for removing with suctionboth cut threads and trimmed edges from the working area of a sewingmachine.

Some commercial sewing machines are provided with a chain cutter whichcuts the leading and trailing ends of thread on the sewing machine. Suchcutter may be actuated manually by the operator of the machine orautomatically in response to signals generated by sensors which detectthe position of the garment being sewn. It is conventional to draw theleading edge of the chain into a tube with suction so that the chain iskept taut and easy to cut and so that the cut threads can bepneumatically conveyed to a waste container for easy disposal.

Further, sewing machines of the type commonly referred to as overlockand/or safety stitch are provided with side cutting knives which trimoff eneven edges of the cloth so that the overlock stitch covers theseams of the two or more parts that are sewn together. This trimmed offportion generally falls in a basket, on the floor or in the operatorslap. At the end of the day these scraps are then usually swept up fordisposal. It has also been suggested in the past to use a separatesuction system for removing the trimmed cloth edges.

The present invention relates to an apparatus which can be used forremoving both the cut threads and the trimmed edges from the workingarea of a sewing machine. As in previous systems, air from a sourceabove atmospheric pressure is injected into an air passage which has aninlet coupled to the region adjacent where the chain is being cut tocreate flow of an air stream through the passage and suction which pullsthe chain through the unit. However, this air stream, created byinjection of the air at a pressure above atmospheric pressure is,according to the invention of this application, injected into a furtherpassage which is coupled to the region adjacent where cloth edges arebeing cut so that the normally wasted air from the exhaust end of thechain cutter unit is employed to create a vacuum to remove wastetrimmings from the cloth. The outlet of the passage into which the airstream carrying the cut threads is injected is then coupled to a wastecontainer for collecting both the cut threads and cut edges fordisposal.

In the embodiment of the invention described in detail below, the unitwhich includes the above mentioned passages is comprised of a firststraight passage, the inlet of which is connected pneumatically to thearea for removing cut edges and a second passage which opens into thefirst passage between the inlet and outlet thereof at an acute angle ofpreferably 22 degrees. The inlet of the second passage is coupledpneumatically to the area for removing chains. A third passage in turnopens into the second passage between the inlet and outlet thereof andis coupled to a source of air above atmospheric pressure, for examplethe air supplied normally in the environment of a sewing factory. Thesecond passage includes a first portion into which the air from thethird passage is injected at an angle preferably of 22 degreesand asecond portion comprising an outer tubular member which opens into thefirst passage and an inner tubular member which guides the air streampassing through the second passage and ends adjacent the opening of theouter tubular member into the first passage, without butting into thefirst passage. The use of the inner and outer tubular members has beenfound to be substantially responsible for the effective momentumtransfer into the first passage and the resultant suction which drawsthe cut ends through the unit into the waste container attached to theoutlet of the first passage.

Many other objects and purposes of the invention will become clear fromthe following detailed description of the drawings.

BRIEF DESCRIPTION OF THEDRAWINGS FIG. 1 shows a perspective view of theinvention of this application mounted in conjunction with a sewingmachine.

FIG. 2 shows a partial sectional view of the unit of which defines thefirst, second and third passages.

FIG.'3 shows a sectional view of the portion of the unit of FIG. 2defining the second and third passages.

DETAILED DESCRIPTION OF THE DRAWINGS Reference is now madeto FIG. 1which shows a perspective view of the invention of this application inuse on a sewing machine. Machine 20 in FIG. 1 is a conventional overlockand/or safety stitch machine which includes a conventional mechanismindicated generally as 22 for cutting the edges of .the'cloth. Machine20 also includes a conventional chain cutter (not shown in FIG. 1) forremoving the cut chain stitches. The embodiment illustrated in FIG. 1includes a unit 24 which is illustrated in sectional view in FIG. 2.Referring to FIG. 2, 'unit 24 defines a firstpassage 26 between an inlet28 and an outlet 30. Inlet 28 is connected to conventional flexible orrigid hose 30 which in turn is disposed by a mounting 32 in the regionwhere the cut edges of the garment are being. produced so that the edgesare drawn into hose 30 and through that hose and passage '26 to wastecontainer 34 which is coupled by L-shaped coupling member 36 to theoutlet 30 of passage 26.

Unit 24 also includes a second passage with an inlet 38 connected by aflexible hose 39 to a conventional chain cutter of sewing machine 20(not shown). A third air passage 40, which can be seen in FIG. 3,injects an air stream at an acute angle, preferably 22 degrees, intosecond passage 42, transferring momentum to the air in that passage andcreating an air stream which flows from the inlet toward the outlet ofthe second passage 42, creating a suction which pulls the cut chainsinto hose 39 and, after they are cut, through hose 39 and second passage42 to be injected into first passage 26 and thereafter conveyed with theair stream in that passage to the outlet 30 and waste container 34.

The air stream which is injected via the third passage 40 is suppliedfrom conventional source, for example, the factory air supply. In thearrangement of FIG. 1, the air supply is connected via hose 50 to atreadle valve 52 which is operated by a conventional sewing machinetreadle 54 to couple and uncouple hoses 50 and 56. Hose 56 is connectedto needle valve 58 of unit 24 as can be best seen in FIG. 2. When needlevalve 58 is open and the treadle valve 52 is actuated by operation oftreadle 54 by the machine operator, an air stream is injected intosecond passage 42 via third passage 40 at an acute angle of 22 degreesto transfer momentum to the air in passage 42 and create air flow.

Second air passage 42 is comprised of a first portion 60 into which thethird passage 40 opens and a second portion 62. Second portion 62includes a pair of concentric cylindrical tubular members 64 and 66 withmember 66 extending within member 64 as'illustrated and guiding air flowin second passage 42. Member 64 opens into the first passage 26 in anelliptically shaped, flat opening. Member 66 terminates adjacent theelliptically shaped opening without butting into passage 26 to create aparticularly advantageous configuration for efficiently transferringmomentum. The angle of the injection between the first passage 26 andthe second passage 42 is preferably 22 degrees in the embodiments ofFIGS. 1-3. The inner tubular member 66 is preferably constructed ofaluminum while the outer tubular member 64 and the remainder of thestructure defining unit 24 are preferably made of plastic which may bepainted or otherwise colored as desired. Needle valve 58 is preferably aconventional metal needle 'valve.

Many changes and modifications in the above described embodiment of theinvention can be of course be carried out without departing from thescope thereof. Accordingly, that scope is intended to be limited only bythe scope of the appended claims.

What is claimed is:

1. Apparatus for removing cut threads and trimmed edges from the workingarea of a sewing machine comprising:

a dual suction unit having a first air passage from an inlet to anoutlet, a second air passage from an inlet to an outlet opening intosaid first passage between the inlet and outlet thereof, at an acuteangle to inject the air stream in said second passage into said firstpassage to transfer momentum and cause an air stream to flow between theinlet and outlet of said first passage and a third air passage openinginto said second passage between the inlet and outlet thereof at anacute angle to inject an air stream at a pressure above atmosphericpressure into said second passage to transfer momentum and cause an airstream to flow between the inlet and outlet of said second passage,

. first hose means'for pneumatically connecting one of said inlets tothe region adjacent where edges are being cut,

second hose means for pneumatically connecting the other of said inletsto the region adjacent where threads are being cut,

third means pneumatically coupling said outlet of said first passage toa waste container, and

means 'for pneumatically connecting said third air passage to a sourceof air at a pressure above atmospheric pressure.

2. Apparatus as in claim 1 further including said source of air, saidwaste container, means for mounting one end of said first hose meansadjacent said region wherein edges are being cut and means for mountingone end of said second hose means adjacent said region where threads arebeing cut.

3. Apparatus as in claim 2 further including a sewing machine having athread cutter and edge cutter.

4. Apparatus as in claim 1 wherein said third air passage opens intosaid second passage in an elliptically shaped opening flat with theinterior surface of said second passage.

5. Apparatus as in claim 1 wherein said first and second passages arecircular in cross section and straight.

6. Apparatus as in claim 1 wherein said first passage includes a firstportion with said third passage opening into said first portion and asecond portion with a first tubular member opening into said firstpassage in an elliptically shaped opening flat with the interior surfaceof said second passage, and a second tubular member within said firstmember conveying said air stream from said first portion to the openingof said first tubular member into said first passage.

1. Apparatus for removing cut threads and trimmed edges from the workingarea of a sewing machine comprising: a dual suction unit having a firstair passage from an inlet to an outlet, a second air passage from aninlet to an outlet opening into said first passage between the inlet andoutlet thereof, at an acute angle to inject the air stream in saidsecond passage into said first passage to transfer momentum and cause anair stream to flow between the inlet and outlet of said first passageand a third air passage opening into said second passage between theinlet and outlet thereof at an acute angle to inject an air stream at apressure above atmospheric pressure into said second passage to transfermomentum and cause an air stream to flow between the inlet and outlet ofsaid second passage, first hose means for pneumatically connecting oneof said inlets to the region adjacent where edges are being cut, secondhose means for pneumatically connecting the other of said inlets to theregion adjacent where threads are being cut, third means pneumaticallycoupling said outlet of said first passage to a waste container, andmeans for pneumatically connecting said third air passage to a source ofair at a pressure above atmospheric pressure.
 2. Apparatus as in claim 1further including said source of air, said waste container, means formounting one end of said first hose means adjacent said region whereinedges are being cut and means for mounting one end of said second hosemeans adjacent said region where threads are being cut.
 3. Apparatus asin claim 2 further including a sewing machine having a thread cutter andedge cutter.
 4. Apparatus as in claim 1 wherein said third air passageopens into said second passage in an elliptically shaped opening flatwith the interior surface of said second passage.
 5. Apparatus as inclaim 1 wherein said first and second passages are circular in crosssection and straight.
 6. Apparatus as in claim 1 wherein said firstpassage includes a first portion with said third passage opening intosaid first portion and a second portion with a first tubular memberopening into said first passage in an elliptically shaped opening flatwith the interior surface of said second passage, and a second tubularmember within said first member conveying said air stream from saidfirst portion to the opening of said first tubular member into saidfirst passage.